I've never seen "Roguelite" as derogatory at all. It's an annoyingly awkwardly neologism, but we legit need a name for the genre that makes heavy use of Roguelike elements (permadeath, procedural generation, emergent combinations of elements) while completely ditching traditional Roguelike gameplay (turn-based RPG dungeon-crawling). Games like Spelunky and FTL and Dead Cells clearly draw inspiration from traditional Roguelikes, but they just as clearly aren't Roguelikes themselves.

I don't think half of the people in Roguelike scene really know - or played - Rogue. It's just a genre name these days, implying permadeath, mazes and (often) ASCII art.

I generally prefer Roguelites and don't really see why the term would be derogatory...